11th January 2016

Are you a manufacturer experiencing a problem with premature failure of a product, or maybe your manufacturing equipment is having trouble staying within tolerance due to a vibration issue? We know solving problems with products and equipment is often complicated and it can be tough to decide who to turn to for help. After completing countless projects for manufacturers just like you, we thought it would be helpful to use what we have learned to create a road map for equipment analysis and troubleshooting of problems of all types.

Here we describe a few rules for system level thinking that may seem obvious but are often overlooked in the rush to bring products to market, achieve production goals, or simply fix a problem. This method moves past discrete services like finite element analysis (FEA) or machine design engineering and considers the 30,000 ft. viewpoint. Intelligent analysis combines effective communication, cross-disciplinary and system level thinking, smart modeling, solutions analysis, and verification. We think high-level thinking is crucial when trying to find a path forward when confronted with a complex problem.

For every complex problem there is an answer that is clear, simple, and wrong.H. L. Mencken

Ask the Right Questions

The discovery process should be a close dialog between the manufacturer and engineer.

As a starting point, having information on product history, function, environment, materials, and loading will help inform how the intelligent analyst can help. Most importantly, the manufacturer has expectations in mind for things like product end-user experience, manufacturing logistics, cost targets and life-cycle. When critical information is not clearly communicated, time and money can be wasted analyzing the wrong thing or providing recommendations that are not feasible. One way to think about it is: "the more questions, the better."

Cross-disciplinary Resources

Failure analyses or product improvement should be considered in light of all relevant disciplines.

Finite element analysis is just one of the tools that can be used to learn something about a process or product. Performing accurate analysis of complex situations requires more knowledge than how to run computer software. It truly requires experience in multiple fields, including materials science, mechanics, soils and foundations, manufacturing processes, measurements, and instrumentation. It can be difficult to find this skill set all in one place.

The intelligent analyst is able to identify the critical areas of knowledge, sources of data, and computations that will lead to a solution, and to recognize when it makes sense to consult an “outside” expert in a specific area. The ability to bring the right people to the problem is perhaps the most important element of this road map. When this is done wisely, a productive synergy and collaboration is usually the result. It is our belief that the client can benefit tremendously from this knowledge leveraging approach.

System Level Thinking

Individual components are tied to a larger system.

It is easy to find a consultant that can perform engineering analysis as a discrete service. What is more difficult is to find one who understands how a problem with a machine or product might be related to something else. Manufacturing facilities are complex arrangements of location, structure, machines and processes leading to a final product.

This can be explained through a simple example of a manufacturing facility where a component in a machine was experiencing high vibration. The plant engineer's first thought was that it was coming from the machinery itself. The intelligent analyst examined the manufacturing facility on a system level by visiting the plant, taking vibration measurements of the slab and equipment, and performing basic analysis on the vibration path. Only after this effort, it was discovered that a nearby piece of rotating machinery was transmitting vibration through the floor slab, soil, equipment foundation, and machine itself to the resonating component. The problem actually originated with another piece of equipment many feet away. Discovery and solution of this critical problem could was only possible with a system level and cross-disciplinary approach to analysis.

The system level approach has helped us solve difficult vibration problems for clients with low manufacturing tolerances.

Make the Right Model

Much can be learned from a simple, well-constructed model. Complexity can follow where needed.

Finite element analysis (FEA) can be thought of as a large number of building blocks put together to define a model of a component or system. Each building block can have its own properties to accurately represent the system. This may sound basic, but it really takes an experienced engineer to construct a model that is both simple and accurate.

A model can use any number of elements (building blocks) with any material properties or boundary conditions. Often times it is found that a simple linear model is much more effective in learning about a particular design problem than a complex non-linear model. In other words, one day of analysis may be able to tell you 80% of what you need to know. Squeezing the last 20% out might require a whole week of analysis. Custom tailoring the amount of analysis required for a particular project is a part of the intelligent analysis approach, and this requires experience and judgement on the part of the engineer.

The Solution Matrix

There may be many possible solutions to a problem or ways to improve a product.

We find that the results of intelligent analysis often lead to many options for fixing a problem with equipment or improving a product. Reports should deliver a clear explanation of all the options to consider. Some might be more expensive to implement and provide the best results while others might be less expensive and provide a solution that is good enough. All options have their pros and cons that can only be decided on after all the facts have been made clear to the manufacturer. Only the manufacturer can determine the "sweet spot."

How would I have known about all of these options without talking to you first?

Follow-up Verification

Computer simulation may not be the only step in the process.

Finite element analysis of a component, sub-assembly, or system is an inexpensive way to simulate a real-world process. Ideally, the analyst is well trained in identifying when simulation has reached its end in terms of useful information. Physical testing, chemical forensic analysis, non-destructive evaluation (NDE) and other real-world methods can be recommended to confirm results of the FEA. This gives the manufacturer more certainty.

For a recent example of follow-up verification, a consumer products manufacturer had a problem with premature breakage of a plastic part subjected to highly variable loading in a physical fitness setting. Intelligent analysis showed that there were problems with high stresses in a critical area near a bolt hole that was changed during a previous material optimization effort. These high stresses led to material fatigue in a relatively low number of cycles. Physical testing was recommended in order to correlate FEA results with experimental load tests. This verified that the model was providing accurate results and helped validate conclusions and recommendations.

Another aspect of this product failure involved the injection molded part's resin formulation. It had been changed recently due to a supplier product line reconfiguration. Material fatigue can be highly sensitive to resin formulation and injection molding process, therefore, a chemical forensic analysis of the failed specimens was recommended.

How can you find these services?

Visit ESI's website for more information or contact us directly to discuss how intelligent analysis can help support your innovative design!

Capabilities:

Simple to advanced stress analysis

Assessment of structural dynamics, vibration and resonance

Fatigue/life-cycle estimates/guidance

Material selection and optimization

Product improvement and economy

Forensic/failure evaluations

Code/regulation compliance

Expert testimony and independent opinions

Vibration measurements

Professional Engineers

ESI has been a part of countless domestic and international projects since 1970. Our engineers, designers and measurement technicians provide certainty to your design process.

We use our depth of experience, ranging from founding partners to recently licensed professionals, and our breadth of knowledge to create multi-disciplinary solutions that benefit our clients.